Scripts are basically written by developers to make websites more dynamic and interactive. But writing a script is not an easy job so many developers copy scripts or use scripts which are available on websites. Some of the scripts are expensive but there are a lot of free and very good scripts. On the internet are several huge web directories with a lot of web development and programming-related resources. These resources are basically created for webmasters, developers, business owners, marketers, coders and programmers, who are looking to build, enhance or improve their web sites and intranets. On these sites you can find not only php or javascripts, there are tons of programming scripts for more than 20 programming languages as well as informational resources including books and tutorials. Most popular of course is Hot Scripts and I would suggest also Codecanyon where are submitted premium very good scripts.